Implement std::error::Error for error types

[FlixCoder]

Thank you for the work on this crate, it looks nice!

I noticed that the error types do not implement std::error::Error, so they cannot be used in standard error handling and not conveniently converted to other errors.

[MortalreminderPT]

Thanks for the suggestion, I'll fix it in the future😃

[MortalreminderPT]

I implemented it in a new commit, you can see the corresponding test by clicking here

[FlixCoder]

Thanks!

[MortalreminderPT]

Thanks!

Thanks for the suggestion, if you encounter problems using the feature, you can reopen the issue😊